My 06 has the sandwich walls you mention with aluminum framing, they are not 16" OC. I've installed the toggle bolts, but not for a tv and not for 13lbs. I did indeed have to push the foam out of the way with a screw driver after drilling the holes. What I did was use the toggles to mount a piece of 3/4" oak, then attached my towel rack to the oak. I went this route so the oak would cover the toggle bolt holes as the small towel rack brackets would not. In practice this worked out fine.